In-line roller skates include a plurality of wheels mounted in line, one behind the other, in a common, longitudinally extending plane. The in-line wheels are typically carried and supported by a lower frame. The lower frame provides a rigid structure or undercarriage for the in-line roller skate wheels and braking system. Conventional in-line roller skates include an upper shoe or boot that is securely attached to the lower frame. The upper shoe provides a support structure for the skater's foot.
In-line roller skates are commonly used outside on uneven sidewalks, bicycle paths, and roadways. The skates are very maneuverable and skaters can achieve speeds of up to 30 miles an hour when skating down a hill--substantially faster than the speeds customarily achieved by skaters using conventional paired-wheel roller skates. In-line roller skating is generally considered to require higher levels of skill, coordination, and strength than conventional paired-wheel roller skating because of the narrow, lateral support base associated with in-line roller skates. Because of the high speeds that can be attained and the relatively greater skill levels required for maneuvering safely when using in-line roller skates, it is important that in-line roller skates have reliable and efficient means for controlling a skater's speed and bringing the skater to a quick, safe, and controlled stop. Specifically, in-line roller skates should have a well-designed and easily applied braking system. This requirement is particularly important for skaters who are less experienced and unable to maneuver so as to avoid collisions.
The primary purpose and function of the braking system on in-line roller skates is to enable a skater to maintain control over speed and direction of motion, to avoid injury to himself and to others. One technique used for braking requires that the skater drag the skate wheels across the ground to create a frictional drag force. This braking method is accomplished by shifting weight over one skate and turning the wheels of the second skate perpendicular to the direction of motion, while forcing the wheels against the skating surface. Alternatively, the skater can use tight-radii S-turns to reduce speed by creating high lateral forces against the wheels, causing the wheels to skid slightly and thereby providing a braking action. However, balancing on one foot while dragging the wheels or making rapid directional changes is difficult, even for expert skaters, particularly at high speeds; therefore, there is a need for a more effective and easily applied braking system, particularly for skaters who are less skilled.
Another approach more commonly used in braking systems for in-line roller skates employs a friction pad mounted at the rear of a skate. A molded rubber pad or plug is mechanically fastened to the rear of the in-line roller skate frame, positioned behind the rearwardmost in-line roller skate wheel, approximately one inch above the skating surface. Braking is achieved by lifting the front of the in-line roller skate and dragging the pad on the skating surface. Since the skater is relying on the friction created between the pad and the skating surface, it is important to provide as much frictional contact between the pad and the skating surface as possible, and to require only a minimal canted angle of the in-line roller skate when braking with the pad.
Until recently, the rear-mounted brake pad used with in-line roller skates has typically comprised a rubber cone- or cylinder-shaped body extending axially from the rear of the skate. While this type of braking system functions adequately, it is desirable to improve the performance so as to make braking as effective and reliable as possible, while minimizing the repositioning of the skate that is required to apply the brake.
In designing an improved rear-mounted brake for an in-line roller skate, it is important that the area off fictional contact and coefficient of friction of the brake pad remain relatively constant over the life of the pad. For example, a brake pad should not require a break-in or wear period to flatten the brake pad sufficiently so that it develops maximum drag. Circular pads commonly used on in-line roller skates have only a portion of the periphery of the circular pad contacting the road surface when the brake pad is new, resulting in poor braking performance until the brake pad has worn sufficiently to provide a greater contact area. In addition to exhibiting poor braking performance when the brake pad is new, there is significant wear of the circular brake pad early in its life, which significantly increases the cant angle of the skate required to bring the brake pad into contact with the skating surface.
A further requirement of braking systems on in-line roller skates is the width of the braking system in relation to the upper shoe and the lower frame. Brake pads should not extend laterally beyond the width of the skate frame, or the brake pad may snag on roadway obstacles, possibly causing the skater to fall. An effective rear-mounted brake must also be configured to avoid snagging when the skater encounters an incline, such as a driveway apron, or when crossing surfaces of irregular height, or cracks in sidewalks or roads. Prior art brakes have avoided this problem by mounting the brake pads sufficiently above the road surface to avoid accidental contact.
While mounting the brake pad higher above the skating surface avoids snagging of the brake system, the skater must often cant the skate through an angle of at least 15 degrees to apply the brake pad to the skating surface, which may jeopardize balance. An inexperienced skater can find it very intimidating to pivot his foot through such an angle while balancing on the other foot in order to apply the braking system.
An additional concern related to the design of braking systems that are attached to the rear of in-line roller skates is that when the brake pad is enlarged to obtain an adequate contact area with the skating surface, the additional forces applied to the brake pad during its use are substantially increased. An excessive force can damage the brake pad mounting or disengage the pad from the lower frame of the skate.
Accordingly, there is a need for a braking system that takes each of these concerns into consideration and enables even less skilled skaters to execute a safe and efficient braking maneuver.